Liquid armature induction pump for an electrically conductive liquid to support a gimbal element of a gyroscope in a hydrostatic bearing

ABSTRACT

A liquid armature induction pump including a stator, liquid armature tube and magnetic shunt for pumping electrically conductive liquid such as mercury so as to hydrostatically support a gimbal element of a gyroscope in a hydrostatic bearing.

United States Patent Jacobson 5] May 16, 1972 LIQUID ARMATURE INDUCTI N P 2,987,001 6 1961 Blake ..103 1 FOR AN ELECTRICALLY 2,990,485 6/1961 Lee ..103/1 x CONDUCTIVE LIQUID TO SUPPORT A 3,018,141 1/1962 Warnock, Jr. ..74/5 x GIMBAL ELEMENT OF A GYROSCOPE g qg e a win e a IN A HYDROSTATIC BEARING 3,362,231 l/1968 Baldwin et al. ..74/5

[72] Inventor: Oscar D. Jacobson, New York, NY

[73] Assignee: The Bendix Corporation [22] Filed: July 1, 1969 [21] Appl. No.: 838,274

[52] [1.8. CL... ..74/5, 74/5.5, 417/50 [51] Int. Cl ..Glc 19/20 [58] Field ofSearch ..74/5, 5.5; 103]], 1 M; 417/50 [5 6] References Cited UNITED STATES PATENTS 2,848,409 8/1958 Szechtman 103/1 X Insu/afmg C0071;

--Flour Primary ExaminerManuel A. Antonakas Attorney-Herbert L. Davis and Plante, Hartz, Smith & Thompson [57] ABSTRACT A liquid armature induction pump including a stator, liquid armature tube and magnetic shunt for pumping electrically conductive liquid such as mercury so as to hydrostatically support a gimbal element of a gyroscope in a hydrostatic bearing.

8 Claims, 2 Drawing Figures P'A'TE'N'TEDHAY 16 m2 SHEET 2 OF 2 F/aar Block Liqu/d 14mm Tube INVENTOR. Oscar .U. Jacobson fl TTORNE Y LIQUID ARMATURE INDUCTION PUMP FOR AN ELECTRICALLY CONDUCTIVE LIQUID TO SUPPORT A GIMBAL ELEMENT OF A GYROSCOPE IN A HYDROSTATIC BEARING CROSS-REFERENCES TO RELATED APPLICATIONS The present application relates to an improved compact pump assembly for supplying a liquid medium under pressure to hydrostatically support a gimbal element of a gyroscope and which may be of a type such as described in a copending U. S. application Ser. No. 807,232 filed Mar. 14, 1969 by Oscar D. Jacobson, for A COMBINATION CENTRIFUGAL AND VISCOUS SHEAR ROTARY PUMP; U. S. application Ser. No. 822,524, filed May 7, 1969, by Oscar D. Jacobson for A FLEXIBLE TUBE PUMP; and in a copending U. S. application Ser. No. 836,056, filed June 24, 1969, by Oscar D. Jacobson, for A Piezoelectric Crystal Operated Pump To Supply Fluid Pressure To Hydrostatically Support Inner Bearings Of A Gyroscope and which applications have been filed by the inventor of the present invention and assigned to The Bendix Corporation, assignee of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a field of low power input pumps which may be utilized to supply liquid pressure medium to hydrostatically support bearings of a gyroscope, in an arrangement in which a fiat armature tube carrying an electrically conductive liquid provides a low reluctance magnetic gap between the stator and magnetic shunt elements of an induction pump so that upon an alternating current being applied to windings of the stator, there is effected a rotating magnetic field which cuts the electrically conducting armature liquid which may beof mercury so as to induce into the armature liquid an electrical current which reacts magnetically with the stator flux so as to drive the armature liquid or mercury through the tube and appropriate output channels into a bearing around the gimbal element of a gyroscope to provide a hydrostatic support for the gimbal element in which the pumped liquid returns through appropriate channels to an input of the induction pump without the need of control valves in either the input or output channels of the pump and in an arrangement in which flow of the mercury to and from the pump may be reversed by merely selecting an appropriate phasing of the alternating energizing current to effect such reverse action.

2. Description of the Prior Art Heretofore there has been provided, as disclosed in a U. S. Pat. No. 3,285,179 granted Nov. 15, 1966, to Edwin L. Resler, Jr. for A MAGNETIC INDUCTION MACHINE an arrangement specifically directed to the use of mercury as a conductive fluid to be pumped in a magnetic induction machine similar in that respect to the mercury armature liquid of the present invention; while in a U. S. Pat. No. 3,251,302 granted May 17, 1966, to Richard S. Baker for A HELICAL ELEC- TROMAGNETIC PUMP there is shown an electromagnetic pump having an AC power phase winding for pumping electrically conductive fluids such as mercury. Further, in U. S. Pat. No. 3,302,573 granted Feb. 7, 1967 to J. L. Ledeen for AN APPARATUS FOR PUMPING LIQUID METALS there is shown a somewhat related apparatus.

However, the flat armature tube for carrying the pumped liquid armature or mercury is of a self-lubricating material which in the arrangement of the subject invention provides (1) a low reluctance magnetic gap between the stator and magnetic shunt of the induction pump and (2) low frictional losses in (3) a compact structural arrangement with a hydrostatic bearing of a gyroscope which in the present invention embodies advantages over that suggested by the structural arrangement of the cited patents.

Thus by the elimination of all moving operating parts except for the pumped conductive armature liquid or mercury carried in an armature tube of a self-lubricating material and the avoidance of control valves in the input and output of the induction pump to a hydrostatic bearing arrangement of the gyroscope, the present invention provides advantages over that of the structure and arrangement of the cited patents in a high efficiency of operation which is in no wise suggested in the disclosures of the patents.

The invention rests then in a conception which simplifies the mechanisms of the prior references and reduces the number of parts, at the same time raising the percent of durability and certainty of operation-in other words, in creating a condition of greater durability and one which is more sure to produce practically the same results in emergency, and not only the greater certainty, but with less expense.

Furthermore, there is no suggestion in the cited reference of the idea of means herein provided whereby the conductive armature liquid or mercury of the induction pump of the present invention may be utilized with the high efiiciency of the present invention to support a gimbal element of a gyroscope in a hydrostatic bearing means.

SUMMARY OF THE INVENTION The present invention relates to a compact liquid armature induction pump in combination with a hydrostatic bearing for a gimbal element of a gyroscope in which the induction pump is mounted in an end plate of a housing of the gyroscope together with stator windings, a liquid armature tube and a magnetic shunt for pumping electrically conductive liquid (mercury) inductively through the armature tube to a hydrostatic bearing for supporting the gimbal of the gyroscope.

An object of the invention is to provide a flat liquid armature tube in the induction pump so arranged as to effect a low reluctance magnetic gap between the stator and stator windings and magnetic shunt of the induction pump whereby .upon an alternating current being applied to energize the stator windings, there is effected a rotating magnetic field which cuts the electrically conducting armature liquid such as mercury carried within the armature tube so that electrical currents induced into the conductive liquid or mercury causes it to react magnetically with the magnetic flux generated by the stator, thus driving the conductive liquid through the flat tube formed of a self-lubricating material with minimum frictional losses and through appropriate output channels into a bearing around the gimbal element of the gyroscope so as to provide a hydrostatic bearing support for the gimbal element and then returning through other appropriate channels to the input of the induction pump without the need of control valves in either the input or output channels of the pump and in an arrangement in which the flow of the conductive armature liquid or mercury to and from the pump may be reversed by merely changing the phasing of the alternating current energizing the stator windings.

Another object of the invention is to provide a conductive armature liquid such as mercury to provide a liquid medium for effecting a hydrostatic support for a gimbal element of a gyroscope and which liquid may be circulated by a simple magnetic induction pump having an alternating current phase stator winding without the need of any moving parts other than the electrically conductive armature liquid such as mercury.

Another object of the invention is to simplify the mechanism for circulating the hydrostatic fluid for supporting a hydrostatic bearing gimbal of a gyroscope by the provision of an induction pump having an armature liquid therein and an arrangement such as to reduce the number of operating parts, while at the same time raising the percent of durability and certainty of operation of the circulating mechanism for the hydrostatic hearing, by in other words creating a condition of greater durability and one which is more sure to produce practically the same results in emergency and not only with greater certainty, but with less expense.

These and other objects and features of the invention are pointed out in the following description in terms of the embodiment thereof which is shown in the accompanying drawings.

DESCRIPTION OF THE DRAWINGS In the drawings in which corresponding parts have been indicated by corresponding numerals.

Fig. 1 is a side view, partly in section taken along the lines 1-1 of FIG. 2, looking in the direction of the arrows and showing a single degree of freedom gyroscope, including in combination a liquid armature induction pump so arranged as to provide an electrically conductive liquid such as mercury under pressure to a hydrostatic bearing means to support a gimbal element of a gyroscope relative'to the'pivotal axis thereof.

FIG. 2 is a fragmentary sectional view taken along the lines 2-2 of FIG. 1 and looking in the direction of the arrows so as to show the operative arrangement of the liquid armature induction pump including a stator, flat armature tube for carrying the armature liquid and magnetic shunt for pumping an electrically conductive armature liquid such as mercury to a hydrostatic bearing for supporting the gimbal element of the gyroscope.

DESCRIPTION OF THE INVENTION Referring now to FIGS. 1 and 2, reference numeral indicates a single degree of freedom gyroscope having a rotor element of conventional type indicated by dash line 12 and rotatably mounted about a first axis 13 in a cylindrical gimbal element 14. A cylindrical housing 16 is provided with end plates and 17 so as to define a substantially cylindrical chamber 18 in which is mounted the gimbal element 14 of the gyroscope 10. The gimbal element 14 may be angularly positioned by the gyroscopic action of the single degree of freedom gyroscope 10 about a second axis 19-19 perpendicular to the first axis 13.

The cylindrical gimbal element 14 is positioned within the cylindrical chamber 18 in a slightly spaced relation to side wall surfaces of the cylindrical housing 16 and the end plates 15 and 17 defining the chamber 18 so as to provide a hydrostatic bearing means for the gimbal element 14, as hereinafter explained.

The cylindrical gimbal element 14 further includes at opposite end portions thereof axially projecting cylindrical shaft portions 20 and 22 having surfaces positioned in spaced relation to surfaces defining recesses 21 and 23 formed in the end plates 15 and 17 of the housing 16. These surfaces are so ar ranged in spaced relation as to cooperate in providing a hydrostatic bearing means upon which the gimbal element 14 may be angularly positioned about the longitudinal axis indicated by the reference numeral 19-19. Thus the surfaces of the shaft portions 20 and 22 cooperate with the surfaces defining the recesses 21 and 23 spaced apart therefrom so that a liquid medium supplied to the spaces between these surfaces form hydrodynamic bearings which support the gimbal element 14 for angular movement about the axis 19-19.

Positioned on one end portion of the housing 16 is a cylindrical casing 25 providing a chamber 25 having a fluid expansion diaphragm 28 mounted in an end of the casing 25 opposite from the housing 16. Mounted in the casing 25 and in spaced relation to the diaphragm 28 is a suitable electronic pick-ofl device indicated generally by the numeral 30 and which may be of a type well known in the art such as a synchro or other suitable electronic signal device having a rotor element 31 operably connected to the shaft portion 22 of the gimbal 14. The electronic pick-off device 30 is electrically connected so as to provide electrical signals in a conventional manner indicative of the angular position of the gimbal 14 cffected by the gyroscope 10.

The electronic pick-off device 30 and the expansion diaphragm 28 are mounted in the cylindrical casing 25 which is in turn mounted on the one end portion of the housing 16. At an opposite end portion of the housing 16 there is mounted another cylindrical casing 34 in which there is in turn mounted a compact induction pump 36 embodying the subject matter of the present invention.

The induction pump 36 includes the end plate 15 so arranged as to provide a pump block sandwiched between an end of the housing 16 and an end plate 40 of the casing 34 provided at an opposite end of the cylindrical casing 34 from the housing 16. The casings 25 and 34 have annular flanges 42 and 44, respectively, projecting radially from the inner ends thereof and secured in position, as shown by FIG. 1, by bolts 46 and 48 screw threadedly engaged in an annular flange 50 projecting radially from the housing 16 and intermediate the opposite ends of the housing 16. As shown by FIG. 2, fastening holes 52 are provided in the flange 50 whereby the gyroscope 10 may be suitably affixed to an aircraft for operation.

The end plate 15 provides a pump block in which there is formed an annular recess 54 in which there is positioned the electromagnetic induction liquid armature pressure pump 36 having an inlet fluid pressure port and an outlet fluid pressure port for. the electrically conductive armature liquid, such as mercury, applied by the pump 36, as hereinafter explained.

An outlet port 66 provided in the end plate 15 leads from the fluid pressure outlet of the pump 36 to a longitudinally extending fluid pressure channel 68 provided in the housing 16. The fluid pressure channel 68 in turn opens at ports 70 into annular fluid pressure channels 74, respectively, which in turn feed through a plurality of ports 78 passing through the wall of the housing 16 and into the cylindrical chamber 18 so as to provide a liquid pressure medium such as mercury about the cylindrical surface of the gimbal element 14 to provide the required pressure and flow to effect a hydrostatic bearing means between the inner surface of the housing 16 and the cylindrical surface of the gimbal element 14 positioned in spaced relation thereto so as to support the cylindrical gimbal element 14 relative to the cylindrical surface of the chamber 18 for angular movement about the axis 19-19.

The recess 21 formed in the pumping block of the end plate 15 opens into the fluid pressure inlet port of the induction pump 36 so as to provide a fluid return passage, while the recess 23 formed in the end plate 17 at the opposite end of the housing 16 provides an outlet for the fluid pressure medium from the cylindrical chamber 18 providing a hydrostatic bearing means for the shaft portion 22 of the gimbal element 14. The recess 23 in turn leads into the chamber 27 in the casing 25 carrying the electronic pick-off device 30 and the fluid expansion diaphragm 28. The pick-off device 30 is suitably electrically insulated from the electrically conductive armature liquid supplied by the pump 26 as the fluid medium for the hydrostatic bearing means.

There is thus provided a fluid pressure chamber 27 in the casing 25, while there is provided in the end plate 17 a fluid pressure return port which opens from the chamber 27 into a longitudinally extending channel 92 formed in the housing 16. The channel 92, as shown by FIG. 1, in turn opens into a return channel 94 formed in the pumping block of the end plate 15, while the channel 94 leads into the recess 21 formed in the pumping block of the end plate 15. Surfaces of shaft portion 20 of the cylindrical gimbal element 14 are, as theretofore explained, positioned in spaced relation to surfaces of the recess 21 in the pumping block of the end plate 15. The recess 21 in turn conducts the returning fluid medium applied through the channel 94 to a return channel 95 formed in the plate 15 and leading to the fluid inlet of the pump 36 providing a hydrostatic bearing means for the shaft portion 20 of the gimbal element 14.

LIQUID ARMATURE INDUCTION PUMP Referring to the form of the invention illustrated by FIGS. 1 and 2, there the pump 36 is shown mounted in an operative relation in the chambers 54 and 56 formed in the pumping block provided by the end plate 15 and casing 34, respectively. The induction pump 36 includes a stator element 108 formed of a suitable stack of annular ferro magnetic plates mounted on a projecting portion 110 of the end plate and arranged in concentric relation to the annular recess 54 in the end plate 15. The assembled stack of the stator plates 108 includes radially projecting teeth 112, as best shown in FIG. 2, and about which teeth are wound stator field windings 114 as shown in FIGS. 1 and 2. The stator element 108 and the field windings 114 are arranged in cooperative relation to an annular flat armature tube 116 carried by an annular magnetic shunt 117, which is also formed of a suitable stack of ferro magnetic plates mounted internally within the end plate 15. The annular flat armature tube 1 16 surrounds the stack of stator plates 108 and is positioned intermediate the magnetic shunt 117 and the stator element 108. The annular flat armature tube 116 is affixed by end parts 118 between opposite side surfaces of the magnetic shunt 117 and inner surfaces of an inner annular recess defined by inner spaced surfaces of the casing 34 and the end plate 15, as best shown in FIG. 1.

The flat annular armature tube 116 carries an electrically conductive armature liquid 120, such as mercury, so that upon the field winding 114 being energized by an appropriate alternating current applied by a suitable source of alternating current 122, there is effected a rotating magnetic field which cuts the electrically conducting armature liquid 120 or mercury so as to induce therein an electrical current. The electrical currents then induced in the armature liquid 120 or mercury reacts with the lines of force of the magnetic flux generated at stator element 108 so as to cause the armature liquid or mercury 120 to be pushed or pumped through the flat armature tube 116 which provides a low reluctance magnetic gap between the stator element 108 and the magnetic shunt 117 and thereby serves to effectively drive and circulate the armature liquid 120 under pressure through the hydrostatic bearing means.

The flat armature tube 116 and end parts 1 18 are formed of a suitable electrical insulating material having wear resistant self-lubricating properties such as a polyflourocarbon material such as Teflon. The currents induced in the armature liquid or mercury 120 act to drive the liquid 120 under the forces of the magnetic flux generated by the stator 108 in the flat tube 116 with a minimum frictional loss due to the self-lubricating properties of the material of the tube 116 and through an outlet passage 125 formed in the stack of plates of the magnetic shunt 117 and having a suitable electrical insulating coating formed of a like self-lubricating electrical insulating material such as Teflon to connect the output of the induction pump 36 to the outlet port 66 provided in the end plate 15.

The outlet port 66 in the plate 15 in turn leads to the longitudinally extending fluid pressure channel 68 provided in the housing 16. The fluid pressure channel 68 conducts the electrically conductive liquid or mercury 120 under the electromagnetic force of the induction pump 36 through ports 70 into annular fluid pressure channels 74 which in turn feed the liquid or mercury 120 through a plurality of ports 78 passing through the wall of the housing 16 and into the cylindrical chamber 18 so as to provide a fluid pressure medium of mercury about the cylindrical surface of the gimbal element 14 to provide the required pressure and flow to effect a hydrostatic bearing means between the inner surface of the housing 16 and the cylindrical surface of the gimbal element 14 positioned in spaced relation thereto so as to support the cylindrical gimbal element 14 relative to the cylindrical surface of the chamber 18 for angular movement about the axis l919.

The recess 21 formed in the pumping block of the end plate 15 opens into the return passage 95 to an inlet passage 127 to the induction pump 36 so as to provide a fluid return passage for the mercury 120, while the recess 23 formed in the end plate 17 at the opposite end of the housing 16 provides an outlet for the fluid pressure medium or mercury 120 from the cylindrical chamber 18 providing a hydrostatic bearing means for the shaft portion 22 of the gimbal element 14. The recess 23 in turn leads into the chamber 27 in the casing carrying the electronic pick-ofi device 30 which is suitably electrically LII insulated from the electrically conductive liquid medium or mercury 120.

There is thus provided a fluid pressure chamber 27 in the casing 25, while there is provided in the end plate 17 a fluid pressure return port for the liquid medium which opens from the chamber 27 into the longitudinally extending channel 92 formed in the housing 16. The channel 92 in turn opens into the return channel 94 formed in the pumping block of the end plate 15 which leads into the recess 21 formed in the pumping block of the end plate 15. Surfaces of shaft portion 20 of the cylindrical gimbal element 14 are, as heretofore explained, positioned in spaced relation to surfaces of the recess 21 in the pumping block of the end plate 15. The recess 21 in turn conducts the returning fluid medium or mercury 120 applied through the channel 94 to a second channel 95 formed in the pumping block of the end plate 15 and leading to the fluid inlet passage 127 formed in the stacked plates of the magnetic shunt 117. The inlet passage 127 to the pump has a suitable electrical insulating coating having self-lubricating properties such as a polyflourocarbon material or Teflon. There is further provided a flow block 130 in the tube 116 separating the inlet end 127 from the outlet end 125 of the armature tube 1 16.

The induction pump 36 thus provides a low friction fluid pressure supply means for the hydrostatic support of the gimbal element 14 with appropriate channeling for returning the liquid medium or mercury from the outlet 125 to the inlet 127 of the induction pump 36.

The present invention includes the following features:

(1) A hydrostatic gyroscopic bearing with a mercury induc tion pump in which a rotating magnetic field is generated by the stator element 108 and which magnetic field cuts the liquid mercury armature captivated in the flat tube 116 formed by the electrically insulating Teflon material having self lubricating properties and arranged intermediate the stator element 108 and magnetic shunt 117 of the induction pump 36. (2) Electrical currents induced in the liquid armature or mercury reacts magnetically with the stator flux so as to push or pump the electrically conductive armature liquid or mercury 120 through the tube 116 which due to the selflubricating properties of the material of the tube 116 and outlet and inlet passages and 127 provide a minimum loss through friction. (3) Moreover the flat liquid armature tube 116 provides a low reluctance magnetic gap between the stator element 108 and magnetic shunt 117. (4) Furthermore appropriate channels lead the pumped armature liquid or mercury 120 from the output 125 and around the gyro gimbal bearing for hydrostatically supporting the gyro gimbal while appropriate channels return the pumped liquid to the inlet 127 of the induction pump 36. (5) The foregoing arrangement provides a pumping action for the hydrostatic fluid in which there are no moving parts except that of the liquid armature fluid 120 which effects the pumping and hydrostatic bearing action.

In the aforenoted action, an appropriate alternating current applied to the stator windings 114 effects a rotating magnetic field which cuts the electrically conductive liquid armature or mercury 120 inducing therein electrical currents which in turn react magnetically with the stator flux driving the electrically conductive liquid 120 through the tube 116 and circulating the liquid in the hydrostatic bearing from the outlet 125 of the induction pump 36 to the inlet 127 thereof. In the aforenoted arrangement the flow of the hydrostatic bearing fluid 120 may be reversed or pulsed by merely appropriately changing the phasing of the alternating current energizing the stator windings 1 14.

While one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangement of the parts, which will now appear obvious to those skilled in the art may be made without departing from the scope of the invention.

What is claimed is:

1. In a gyroscope of a type including housing means;

fluid supply means within said housing means;

a gimbal element carrying a gyroscopic rotor rotatable about a first axis;

hydrostatic bearing means operable by said fluid supply means to support said gimbal element within said housing for pivotal movement about a second axis perpendicular to the first axis;

the improvement in which said housing means includes a block mounted at one end of the housing means;

the fluid supply means includes an induction pump;

the induction pump including field windings, a magnetic shunt and an annular tubular member fixedly mounted in the end block;

. said annular tubular member being positioned intermediate the field windings and the magnetic shunt,

the annular tubular member including an electrically conductive fluid medium therein inductively coupled to the field windings, inlet and outlet port means for the fluid medium opening into an interior channel in the tubular member and from the interior channel of the tubular member, and a blocking element in a portion of the annular tubular member to prevent flow of the fluid medium through said portion of the tubular member between the inlet and outlet port means; and

alternating current supply means to energize the field windings to provide electromagnetic forces for supplying the fluid medium to the hydrostatic bearing means under pressure.

2. The improvement defined by claim 1 in which the tubular member includes a relatively flat annular tubular member positioned in concentric relation intermediate the field windings and the magnetic shunt so that the electrically conductive fluid medium within the tubular member provides a relatively low reluctance magnetic gap between the field windings and the magnetic shunt.

3. The improvement defined by claim 1 in which the tubular member includes a relatively flat annular tubular member positioned in concentric relation intermediate the field windings and the magnetic shunt so that the electrically conductive fluid medium within the tubular member provides a relatively low reluctance magnetic gap between the field windings and the magnetic shunt;

the annular tubular member being of an electrical resistant self-lubricating material so as to provide low frictional losses in the supplying of the fluid medium to the hydrostatic bearing means under pressure.

4. The improvement defined by claim 1 including the tubular member being of a self-lubricating material so as to provide low frictional losses in the supplying of the fluid medium to the hydrostatic bearing means under pressure.

5. In a gyroscope of a type including housing means;

fluid supply means within said housing means;

a gimbal element carrying a gyroscopic rotor rotatable about a first axis;

hydrostatic bearing means operable by said fluid supply means to support said gimbal element within said housing for pivotal movement about a second axis perpendicular to the first axis;

the improvement in which said housing means includes a block mounted at one end of the housing means;

the fluid supply means includes an induction pump:

the induction pump including field windings, a magnetic shunt and a tubular member fixedly mounted in the end block;

said tubular member being positioned intermediate the field windings and the magnetic shunt, I

the tubular member including an electrically conductive fluid medium therein inductively coupled to the field windings, and inlet and outlet port means for the fluid medium opening into an interior channel in the tubular member and from the interior channel of the tubular member;

valternating current supply means to energize the field windings to Iprovide electromagnetic forces; and the electrical y conductive fluid medium In the tubular member comprising a liquid medium of mercury providing an electrically conductive mercury armature so that said liquid medium may be supplied under electromagnetic forces generated by the energized field windings of the induction pump to the hydrostatic bearing means for supporting the gimbal element in said liquid medium of mercury under pressure of the electromagnetic forces applied thereto.

6. The improvement defined by claim 5 in which the tubular member includes a relatively flat annular tubular member positioned in concentric relation intermediate the field windings and the magnetic shunt so that the electrically conductive liquid medium of mercury within the tubular member provides a relatively low reluctance magnetic gap between the field windings and the magnetic shunt.

7. The improvement defined by claim 6 including the annular tubular member being of an electrical resistant selflubricating material so as to provide low frictional losses in the supplying of the liquid medium of mercury of the hydrostatic bearing means under said pressure.

8. The improvement defined by claim 7 including a blocking element in a portion of the annular tubular member to prevent flow of the liquid medium of mercury through said portion of the tubular member between the inlet and outlet port means.

* it k 

1. In a gyroscope of a type including housing means; fluid supply means within said housing means; a gimbal element carrying a gyroscopic rotor rotatable about a first axis; hydrostatic bearing means operable by said fluid supply means to support said gimbal element within said housing for pivotal movement about a second axis perpendicular to the first axis; the improvement in which said housing means includes a block mounted at one end of the housing means; the fluid supply means includes an induction pump; the induction pump including field windings, a magnetic shunt and an annular tubular member fixedly mounted in the end block; said annular tubular member being positioned intermediate the field windings and the magnetic shunt, the annular tubular member including an electrically conductive fluid medium therein inductively coupled to the field windings, inlet and outlet port means for the fluid medium opening into an interior channel in the tubular member and from the interior channel of the tubular member, and a blocking element in a portion of the annular tubular member to prevent flow of the fluid medium through said portion of the tubular member between the inlet and outlet port means; and alternating current supply means to energize the field windings to provide electromagnetic forces for supplying the fluid medium to the hydrostatic bearing means under pressure.
 2. The improvement defined by claim 1 in which the tubular member includes a relatively flat annular tubular member positioned in concentric relation intermediate the field windings and the magnetic shunt so that the electrically conductive fluid medium within the tubular member provides a relatively low reluctance magnetic gap between the field windings and the magnetic shunt.
 3. The improvement defined by claim 1 in which the tubular member includes a relatively flat annular tubular member positioned in concentric relation intermediate the field windings and the magnetic shunt so that the electrically conductive fluid medium within the tubular member provides a relatively low reluctance magnetic gap between the field windings and the magnetic shunt; the annular tubular member being of an electrical resistant self-lubricating material so as to provide low frictional losses in the supplying of the fluid medium to the hydrostatic bearing means under pressure.
 4. The improvement defined by claim 1 including the tubular member being of a self-lubricating material so as to provide low frictional losseS in the supplying of the fluid medium to the hydrostatic bearing means under pressure.
 5. In a gyroscope of a type including housing means; fluid supply means within said housing means; a gimbal element carrying a gyroscopic rotor rotatable about a first axis; hydrostatic bearing means operable by said fluid supply means to support said gimbal element within said housing for pivotal movement about a second axis perpendicular to the first axis; the improvement in which said housing means includes a block mounted at one end of the housing means; the fluid supply means includes an induction pump: the induction pump including field windings, a magnetic shunt and a tubular member fixedly mounted in the end block; said tubular member being positioned intermediate the field windings and the magnetic shunt, the tubular member including an electrically conductive fluid medium therein inductively coupled to the field windings, and inlet and outlet port means for the fluid medium opening into an interior channel in the tubular member and from the interior channel of the tubular member; alternating current supply means to energize the field windings to provide electromagnetic forces; and the electrically conductive fluid medium in the tubular member comprising a liquid medium of mercury providing an electrically conductive mercury armature so that said liquid medium may be supplied under electromagnetic forces generated by the energized field windings of the induction pump to the hydrostatic bearing means for supporting the gimbal element in said liquid medium of mercury under pressure of the electromagnetic forces applied thereto.
 6. The improvement defined by claim 5 in which the tubular member includes a relatively flat annular tubular member positioned in concentric relation intermediate the field windings and the magnetic shunt so that the electrically conductive liquid medium of mercury within the tubular member provides a relatively low reluctance magnetic gap between the field windings and the magnetic shunt.
 7. The improvement defined by claim 6 including the annular tubular member being of an electrical resistant self-lubricating material so as to provide low frictional losses in the supplying of the liquid medium of mercury of the hydrostatic bearing means under said pressure.
 8. The improvement defined by claim 7 including a blocking element in a portion of the annular tubular member to prevent flow of the liquid medium of mercury through said portion of the tubular member between the inlet and outlet port means. 